usr/src/common/util/sscanf.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright (c) 1990, 1993
  24  *      The Regents of the University of California.  All rights reserved.
  25  *
  26  * This code is derived from software contributed to Berkeley by
  27  * Chris Torek.
  28  *
  29  * Redistribution and use in source and binary forms, with or without
  30  * modification, are permitted provided that the following conditions
  31  * are met:
  32  * 1. Redistributions of source code must retain the above copyright
  33  *    notice, this list of conditions and the following disclaimer.
  34  * 2. Redistributions in binary form must reproduce the above copyright
  35  *    notice, this list of conditions and the following disclaimer in the
  36  *    documentation and/or other materials provided with the distribution.
  37  * 4. Neither the name of the University nor the names of its contributors
  38  *    may be used to endorse or promote products derived from this software
  39  *    without specific prior written permission.
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * From: Id: vfscanf.c,v 1.13 1998/09/25 12:20:27 obrien Exp
  54  * From: static char sccsid[] = "@(#)strtol.c   8.1 (Berkeley) 6/4/93";
  55  * From: static char sccsid[] = "@(#)strtoul.c  8.1 (Berkeley) 6/4/93";
  56  */
  57
  58
  59 /*
  60  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
  61  * Use is subject to license terms.
  62  */
  63
  64 #pragma ident   "%Z%%M% %I%     %E% SMI"
  65
  66 #include <sys/types.h>
  67 #include <sys/systm.h>
  68 #include <sys/ctype.h>
  69 #include <sys/sunddi.h>
  70 #include <util/sscanf.h>
  71
  72 #define BUF             32      /* Maximum length of numeric string. */
  73
  74 /*
  75  * Flags used during conversion.
  76  */
  77 #define LONG            0x01    /* l: long or double */
  78 #define SHORT           0x04    /* h: short */
  79 #define SUPPRESS        0x08    /* suppress assignment */
  80 #define POINTER         0x10    /* weird %p pointer (`fake hex') */
  81 #define NOSKIP          0x20    /* do not skip blanks */
  82
  83 /*
  84  * The following are used in numeric conversions only:
  85  * SIGNOK, NDIGITS, DPTOK, and EXPOK are for floating point;
  86  * SIGNOK, NDIGITS, PFXOK, and NZDIGITS are for integral.
  87  */
  88 #define SIGNOK          0x40    /* +/- is (still) legal */
  89 #define NDIGITS         0x80    /* no digits detected */
  90
  91 #define DPTOK           0x100   /* (float) decimal point is still legal */
  92 #define EXPOK           0x200   /* (float) exponent (e+3, etc) still legal */
  93
  94 #define PFXOK           0x100   /* 0x prefix is (still) legal */
  95 #define NZDIGITS        0x200   /* no zero digits detected */
  96
  97 /*
  98  * Conversion types.
  99  */
 100 #define CT_CHAR         0       /* %c conversion */
 101 #define CT_CCL          1       /* %[...] conversion */
 102 #define CT_STRING       2       /* %s conversion */
 103 #define CT_INT          3       /* integer, i.e., strtoq or strtouq */
 104
 105 static const uchar_t *set_ccl(char *, const uchar_t *);
 106
 107 #define isspace(ch)     (((ch) == ' ') || ((ch) == '\r') || ((ch) == '\n') || \
 108                         ((ch) == '\t') || ((ch) == '\f'))
 109
 110 int
 111 vsscanf(const char *inp, char const *fmt0, va_list ap)
 112 {
 113         int inr;
 114         const uchar_t *fmt = (const uchar_t *)fmt0;
 115         int c;                  /* character from format, or conversion */
 116         size_t width;           /* field width, or 0 */
 117         char *p;                /* points into all kinds of strings */
 118         int n;                  /* handy integer */
 119         int flags;              /* flags as defined above */
 120         char *p0;               /* saves original value of p when necessary */
 121         int nassigned;          /* number of fields assigned */
 122         int nconversions;       /* number of conversions */
 123         int nread;              /* number of characters consumed from fp */
 124         int base;               /* base argument to strtoq/strtouq */
 125         int sconv;              /* do signed conversion */
 126         char ccltab[256];       /* character class table for %[...] */
 127         char buf[BUF];          /* buffer for numeric conversions */
 128
 129         /* `basefix' is used to avoid `if' tests in the integer scanner */
 130         static short basefix[17] =
 131                 { 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
 132
 133         inr = strlen(inp);
 134
 135         sconv = 0;
 136         nassigned = 0;
 137         nconversions = 0;
 138         nread = 0;
 139         base = 0;
 140         for (;;) {
 141                 c = *fmt++;
 142                 if (c == 0)
 143                         return (nassigned);
 144                 if (isspace(c)) {
 145                         while (inr > 0 && isspace(*inp))
 146                                 nread++, inr--, inp++;
 147                         continue;
 148                 }
 149                 if (c != '%')
 150                         goto literal;
 151                 width = 0;
 152                 flags = 0;
 153                 /*
 154                  * switch on the format.  continue if done;
 155                  * break once format type is derived.
 156                  */
 157 again:          c = *fmt++;
 158                 switch (c) {
 159                 case '%':
 160 literal:
 161                         if (inr <= 0)
 162                                 goto input_failure;
 163                         if (*inp != c)
 164                                 goto match_failure;
 165                         inr--, inp++;
 166                         nread++;
 167                         continue;
 168
 169                 case '*':
 170                         flags |= SUPPRESS;
 171                         goto again;
 172                 case 'l':
 173                         flags |= LONG;
 174                         goto again;
 175                 case 'h':
 176                         flags |= SHORT;
 177                         goto again;
 178
 179                 case '0': case '1': case '2': case '3': case '4':
 180                 case '5': case '6': case '7': case '8': case '9':
 181                         width = width * 10 + c - '0';
 182                         goto again;
 183
 184                 /*
 185                  * Conversions.
 186                  *
 187                  */
 188                 case 'd':
 189                         c = CT_INT;
 190                         sconv = 1;
 191                         base = 10;
 192                         break;
 193
 194                 case 'i':
 195                         c = CT_INT;
 196                         sconv = 1;
 197                         base = 0;
 198                         break;
 199
 200                 case 'o':
 201                         c = CT_INT;
 202                         base = 8;
 203                         break;
 204
 205                 case 'u':
 206                         c = CT_INT;
 207                         base = 10;
 208                         break;
 209
 210                 case 'x':
 211                         flags |= PFXOK; /* enable 0x prefixing */
 212                         c = CT_INT;
 213                         base = 16;
 214                         break;
 215
 216                 case 's':
 217                         c = CT_STRING;
 218                         break;
 219
 220                 case '[':
 221                         fmt = set_ccl(ccltab, fmt);
 222                         flags |= NOSKIP;
 223                         c = CT_CCL;
 224                         break;
 225
 226                 case 'c':
 227                         flags |= NOSKIP;
 228                         c = CT_CHAR;
 229                         break;
 230
 231                 case 'p':       /* pointer format is like hex */
 232                         flags |= POINTER | PFXOK;
 233                         c = CT_INT;
 234                         base = 16;
 235                         break;
 236
 237                 case 'n':
 238                         nconversions++;
 239                         if (flags & SUPPRESS)   /* ??? */
 240                                 continue;
 241                         if (flags & SHORT)
 242                                 *va_arg(ap, short *) = (short)nread;
 243                         else if (flags & LONG)
 244                                 *va_arg(ap, long *) = (long)nread;
 245                         else
 246                                 *va_arg(ap, int *) = nread;
 247                         continue;
 248                 }
 249
 250                 /*
 251                  * We have a conversion that requires input.
 252                  */
 253                 if (inr <= 0)
 254                         goto input_failure;
 255
 256                 /*
 257                  * Consume leading white space, except for formats
 258                  * that suppress this.
 259                  */
 260                 if ((flags & NOSKIP) == 0) {
 261                         while (isspace(*inp)) {
 262                                 nread++;
 263                                 if (--inr > 0)
 264                                         inp++;
 265                                 else
 266                                         goto input_failure;
 267                         }
 268                         /*
 269                          * Note that there is at least one character in
 270                          * the buffer, so conversions that do not set NOSKIP
 271                          * can no longer result in an input failure.
 272                          */
 273                 }
 274
 275                 /*
 276                  * Do the conversion.
 277                  */
 278                 switch (c) {
 279
 280                 case CT_CHAR:
 281                         /* scan arbitrary characters (sets NOSKIP) */
 282                         if (width == 0)
 283                                 width = 1;
 284                         if (flags & SUPPRESS) {
 285                                 size_t sum = 0;
 286
 287                                 if ((n = inr) < width) {
 288                                         sum += n;
 289                                         width -= n;
 290                                         inp += n;
 291                                         if (sum == 0)
 292                                                 goto input_failure;
 293                                 } else {
 294                                         sum += width;
 295                                         inr -= width;
 296                                         inp += width;
 297                                 }
 298                                 nread += sum;
 299                         } else {
 300                                 bcopy(inp, va_arg(ap, char *), width);
 301                                 inr -= width;
 302                                 inp += width;
 303                                 nread += width;
 304                                 nassigned++;
 305                         }
 306                         nconversions++;
 307                         break;
 308
 309                 case CT_CCL:
 310                         /* scan a (nonempty) character class (sets NOSKIP) */
 311                         if (width == 0)
 312                                 width = (size_t)~0;     /* `infinity' */
 313                         /* take only those things in the class */
 314                         if (flags & SUPPRESS) {
 315                                 n = 0;
 316                                 while (ccltab[(unsigned char)*inp]) {
 317                                         n++, inr--, inp++;
 318                                         if (--width == 0)
 319                                                 break;
 320                                         if (inr <= 0) {
 321                                                 if (n == 0)
 322                                                         goto input_failure;
 323                                                 break;
 324                                         }
 325                                 }
 326                                 if (n == 0)
 327                                         goto match_failure;
 328                         } else {
 329                                 p0 = p = va_arg(ap, char *);
 330                                 while (ccltab[(unsigned char)*inp]) {
 331                                         inr--;
 332                                         *p++ = *inp++;
 333                                         if (--width == 0)
 334                                                 break;
 335                                         if (inr <= 0) {
 336                                                 if (p == p0)
 337                                                         goto input_failure;
 338                                                 break;
 339                                         }
 340                                 }
 341                                 n = p - p0;
 342                                 if (n == 0)
 343                                         goto match_failure;
 344                                 *p = 0;
 345                                 nassigned++;
 346                         }
 347                         nread += n;
 348                         nconversions++;
 349                         break;
 350
 351                 case CT_STRING:
 352                         /* like CCL, but zero-length string OK, & no NOSKIP */
 353                         if (width == 0)
 354                                 width = (size_t)~0;
 355                         if (flags & SUPPRESS) {
 356                                 n = 0;
 357                                 while (!isspace(*inp)) {
 358                                         n++, inr--, inp++;
 359                                         if (--width == 0)
 360                                                 break;
 361                                         if (inr <= 0)
 362                                                 break;
 363                                 }
 364                                 nread += n;
 365                         } else {
 366                                 p0 = p = va_arg(ap, char *);
 367                                 while (!isspace(*inp)) {
 368                                         inr--;
 369                                         *p++ = *inp++;
 370                                         if (--width == 0)
 371                                                 break;
 372                                         if (inr <= 0)
 373                                                 break;
 374                                 }
 375                                 *p = 0;
 376                                 nread += p - p0;
 377                                 nassigned++;
 378                         }
 379                         nconversions++;
 380                         continue;
 381
 382                 case CT_INT:
 383                         /* scan an integer as if by strtoq/strtouq */
 384                         /* size_t is unsigned, hence this optimisation */
 385                         if (--width > sizeof (buf) - 2)
 386                                 width = sizeof (buf) - 2;
 387                         width++;
 388                         flags |= SIGNOK | NDIGITS | NZDIGITS;
 389                         for (p = buf; width; width--) {
 390                                 c = *inp;
 391                                 /*
 392                                  * Switch on the character; `goto ok'
 393                                  * if we accept it as a part of number.
 394                                  */
 395                                 switch (c) {
 396
 397                                 /*
 398                                  * The digit 0 is always legal, but is
 399                                  * special.  For %i conversions, if no
 400                                  * digits (zero or nonzero) have been
 401                                  * scanned (only signs), we will have
 402                                  * base==0.  In that case, we should set
 403                                  * it to 8 and enable 0x prefixing.
 404                                  * Also, if we have not scanned zero digits
 405                                  * before this, do not turn off prefixing
 406                                  * (someone else will turn it off if we
 407                                  * have scanned any nonzero digits).
 408                                  */
 409                                 case '0':
 410                                         if (base == 0) {
 411                                                 base = 8;
 412                                                 flags |= PFXOK;
 413                                         }
 414                                         if (flags & NZDIGITS)
 415                                             flags &= ~(SIGNOK|NZDIGITS|NDIGITS);
 416                                         else
 417                                             flags &= ~(SIGNOK|PFXOK|NDIGITS);
 418                                         goto ok;
 419
 420                                 /* 1 through 7 always legal */
 421                                 case '1': case '2': case '3':
 422                                 case '4': case '5': case '6': case '7':
 423                                         base = basefix[base];
 424                                         flags &= ~(SIGNOK | PFXOK | NDIGITS);
 425                                         goto ok;
 426
 427                                 /* digits 8 and 9 ok iff decimal or hex */
 428                                 case '8': case '9':
 429                                         base = basefix[base];
 430                                         if (base <= 8)
 431                                                 break;  /* not legal here */
 432                                         flags &= ~(SIGNOK | PFXOK | NDIGITS);
 433                                         goto ok;
 434
 435                                 /* letters ok iff hex */
 436                                 case 'A': case 'B': case 'C':
 437                                 case 'D': case 'E': case 'F':
 438                                 case 'a': case 'b': case 'c':
 439                                 case 'd': case 'e': case 'f':
 440                                         /* no need to fix base here */
 441                                         if (base <= 10)
 442                                                 break;  /* not legal here */
 443                                         flags &= ~(SIGNOK | PFXOK | NDIGITS);
 444                                         goto ok;
 445
 446                                 /* sign ok only as first character */
 447                                 case '+': case '-':
 448                                         if (flags & SIGNOK) {
 449                                                 flags &= ~SIGNOK;
 450                                                 goto ok;
 451                                         }
 452                                         break;
 453
 454                                 /* x ok iff flag still set & 2nd char */
 455                                 case 'x': case 'X':
 456                                         if (flags & PFXOK && p == buf + 1) {
 457                                                 base = 16;      /* if %i */
 458                                                 flags &= ~PFXOK;
 459                                                 goto ok;
 460                                         }
 461                                         break;
 462                                 }
 463
 464                                 /*
 465                                  * If we got here, c is not a legal character
 466                                  * for a number.  Stop accumulating digits.
 467                                  */
 468                                 break;
 469                 ok:
 470                                 /*
 471                                  * c is legal: store it and look at the next.
 472                                  */
 473                                 *p++ = c;
 474                                 if (--inr > 0)
 475                                         inp++;
 476                                 else
 477                                         break;          /* end of input */
 478                         }
 479                         /*
 480                          * If we had only a sign, it is no good; push
 481                          * back the sign.  If the number ends in `x',
 482                          * it was [sign] '0' 'x', so push back the x
 483                          * and treat it as [sign] '0'.
 484                          */
 485                         if (flags & NDIGITS) {
 486                                 if (p > buf) {
 487                                         inp--;
 488                                         inr++;
 489                                 }
 490                                 goto match_failure;
 491                         }
 492                         c = ((uchar_t *)p)[-1];
 493                         if (c == 'x' || c == 'X') {
 494                                 --p;
 495                                 inp--;
 496                                 inr++;
 497                         }
 498                         if ((flags & SUPPRESS) == 0) {
 499                                 ulong_t res;
 500
 501                                 *p = 0;
 502                                 if (sconv)
 503                                         (void) ddi_strtol(buf, (char **)NULL,
 504                                             base, (long *)(&res));
 505                                 else
 506                                         (void) ddi_strtoul(buf, (char **)NULL,
 507                                             base, &res);
 508                                 if (flags & POINTER)
 509                                         *va_arg(ap, void **) =
 510                                                 (void *)(uintptr_t)res;
 511                                 else if (flags & SHORT)
 512                                         *va_arg(ap, short *) = (short)res;
 513                                 else if (flags & LONG)
 514                                         *va_arg(ap, long *) = (long)res;
 515                                 else
 516                                         *va_arg(ap, int *) = (int)res;
 517                                 nassigned++;
 518                         }
 519                         nread += p - buf;
 520                         nconversions++;
 521                         break;
 522
 523                 }
 524         }
 525 input_failure:
 526         return (nconversions != 0 ? nassigned : -1);
 527 match_failure:
 528         return (nassigned);
 529 }
 530
 531 /*
 532  * Fill in the given table from the scanset at the given format
 533  * (just after `[').  Return a pointer to the character past the
 534  * closing `]'.  The table has a 1 wherever characters should be
 535  * considered part of the scanset.
 536  */
 537 static const uchar_t *
 538 set_ccl(char *tab, const uchar_t *fmt)
 539 {
 540         int c, n, v;
 541
 542         /* first `clear' the whole table */
 543         c = *fmt++;             /* first char hat => negated scanset */
 544         if (c == '^') {
 545                 v = 1;          /* default => accept */
 546                 c = *fmt++;     /* get new first char */
 547         } else
 548                 v = 0;          /* default => reject */
 549
 550         /* XXX: Will not work if sizeof(tab*) > sizeof(char) */
 551         for (n = 0; n < 256; n++)
 552                 tab[n] = v;     /* memset(tab, v, 256) */
 553
 554         if (c == 0)
 555                 return (fmt - 1); /* format ended before closing ] */
 556
 557         /*
 558          * Now set the entries corresponding to the actual scanset
 559          * to the opposite of the above.
 560          *
 561          * The first character may be ']' (or '-') without being special;
 562          * the last character may be '-'.
 563          */
 564         v = 1 - v;
 565         for (;;) {
 566                 tab[c] = v;             /* take character c */
 567 doswitch:
 568                 n = *fmt++;             /* and examine the next */
 569                 switch (n) {
 570
 571                 case 0:                 /* format ended too soon */
 572                         return (fmt - 1);
 573
 574                 case '-':
 575                         /*
 576                          * A scanset of the form
 577                          *      [01+-]
 578                          * is defined as `the digit 0, the digit 1,
 579                          * the character +, the character -', but
 580                          * the effect of a scanset such as
 581                          *      [a-zA-Z0-9]
 582                          * is implementation defined.  The V7 Unix
 583                          * scanf treats `a-z' as `the letters a through
 584                          * z', but treats `a-a' as `the letter a, the
 585                          * character -, and the letter a'.
 586                          *
 587                          * For compatibility, the `-' is not considerd
 588                          * to define a range if the character following
 589                          * it is either a close bracket (required by ANSI)
 590                          * or is not numerically greater than the character
 591                          * we just stored in the table (c).
 592                          */
 593                         n = *fmt;
 594                         if (n == ']' || n < c) {
 595                                 c = '-';
 596                                 break;  /* resume the for(;;) */
 597                         }
 598                         fmt++;
 599                         /* fill in the range */
 600                         do {
 601                             tab[++c] = v;
 602                         } while (c < n);
 603                         c = n;
 604                         /*
 605                          * Alas, the V7 Unix scanf also treats formats
 606                          * such as [a-c-e] as `the letters a through e'.
 607                          * This too is permitted by the standard....
 608                          */
 609                         goto doswitch;
 610                         /* NOTREACHED */
 611
 612                 case ']':               /* end of scanset */
 613                         return (fmt);
 614
 615                 default:                /* just another character */
 616                         c = n;
 617                         break;
 618                 }
 619         }
 620         /* NOTREACHED */
 621 }
 622
 623 int
 624 sscanf(const char *ibuf, const char *fmt, ...)
 625 {
 626         va_list ap;
 627         int ret;
 628
 629         va_start(ap, fmt);
 630         ret = vsscanf(ibuf, fmt, ap);
 631         va_end(ap);
 632         return (ret);
 633 }